真空浸渍辅助曲酸对鲜切马铃薯多酚氧化酶和过氧化物酶活性的抑制作用

Effect of vacuum impregnation assisted withkojic acid on inhibition of polyphenol oxidase and peroxidase activities in fresh-cut potato

以鲜切马铃薯为试验材料,采用真空浸渍辅助曲酸抑制其多酚氧化酶(PPO)和过氧化物酶(POD)活性。首先通过单因素试验,考察真空时间、浸渍时间、曲酸质量分数3个因素对PPO和POD活性的抑制效果。在此基础上,利用响应面法优化上述3个条件,筛选出抑制PPO和POD活性的最佳条件。结果表明,通过单因素试验得到抑制PPO和POD活性的最佳条件是:真空时间为12 min,浸渍时间为8 min,曲酸质量分数为0.75%。响应面优化试验得到的抑制PPO的最佳条件是:真空时间为12 min,浸渍时间为7.5 min,曲酸质量分数为0.76%;在此条件下所得PPO活性为412.26 U/ml,与理论值(403.369 U/ml)的相对误差在2.2%左右。抑制POD的最佳条件是:真空时间为12 min,浸渍时间为8 min,曲酸质量分数为0.75%;在此条件下所得PPO活性为97.75 U/ml,与理论值95.898 U/ml的相对误差在1.93%左右。证明回归模型具有较好的拟合度,可以对真空浸渍辅助曲酸抑制鲜切马铃薯PPO和POD活性进行分析和预测。

Using fresh-cut potato asexperimental material,the activity of polyphenol oxidase(PPO) and peroxidase(POD) in fresh-cut potato was inhibited by vacuum impregnation assisted with kojic acid.First,the inhibition effect of vacuum time,impregnation time and kojic acid solution concentration on PPO and POD activitywasinvestigated by single factor test. Then,the response surface method was used to optimize the best conditions for inhibiting the activity of PPO and POD.The results showed that the best conditions for inhibiting theactivity of PPO and POD were obtained by single factor test: the vacuum time was 12 min,the immersion time was 8 min,and the mass fraction of kojic acid was 0.75%.Thebest conditions for inhibiting theactivity of PPO were optimizedby the response surface test: the vacuum time was 12 min,the immersion time was 7.5 min,and the mass fraction of kojic acid was 0.76%.Under this condition,the PPO activity obtained was 412.26 U/ml,and the relative error between the experiment result and the theoretical data(403.369 U/ml) was about 2.2%.Thebest conditions for inhibiting theactivity of POD were optimizedby the response surface test: the vacuum time was 12 min,the immersion time was 8 min,and the mass fraction of kojic acid was 0.75%.Under this condition,the POD activity obtained was 97.75 U/ml,and the relative error between the experiment result and the theoretical data(95.898 U/ml) was about 1.93%.It is proved that the regression model has a good fitting degree and can be used to analyze and predict the activity of PPO and POD in fresh-cut potato by vacuum impregnation assisted with kojic acid.